Bette Davis had originally wanted Laurence Olivier for the role of Lord Essex, claiming that Errol Flynn could not speak blank verse well. She remained extremely upset about this through the entire filming, and Flynn and Davis never worked again together in a film, but according to Olivia de Havilland, she and Davis screened the film again a short while before Davis's stroke. At film's end, Davis turned to de Havilland and declared that she had been wrong about Flynn, and that he gave a fine performance as Essex.
Errol Flynn and Bette Davis disliked each other, and when Elizabeth slaps Essex in front of the entire court, Davis hauled off and unexpectedly belted Flynn for real, during a dress rehearsal, a blow that brought stars to his eyes. Flynn described in his biography that he had decided that if Davis hit him during filming, he would have to hit her back. However, she did not actually hit him in the take that ended up in the final version of the film.
As well as shaving two inches off her hairline at the forehead, Bette Davis also had her eyebrows removed. She later complained that they never grew back properly and that ever after she had to draw them in with an eyebrow pencil.
Bette Davis (31 at the time the movie was made) was less than half the actual age of Queen Elizabeth was at the time of the events of the film. Queen Elizabeth was 63 in 1596. Errol Flynn was only one year younger than her, although Essex was 32 years younger than Elizabeth.
Charles Laughton, whom Bette Davis greatly admired, visited her on the set. Seeing him she greeted him with, "Hi, Pop!" referencing his Oscar-winning portrayal Elizabeth's father Henry VIII in The Private Life of Henry VIII. (1933). While talking together in a corner of the set, the thirty-one year old actress confessed to him that she felt she had bitten off more than she could chew in playing an older Elizabeth. According to the Davis biography 'Fasten Your Seat Belts', he replied, "Never stop daring to hang yourself, Bette!"
The relationship between Elizabeth and Essex bordered on the incestuous. His maternal great-grandmother Mary Boleyn was a sister of Anne Boleyn, mother of Queen Elizabeth I, making him a cousin of the Queen, and there were rumours that his grandmother, Catherine Carey, a close friend of Queen Elizabeth's, was Henry VIII's illegitimate daughter. Moreover, his mother was married to Robert Dudley, Earl of Leicester, the Queen's most beloved courtier and rumoredly her secret lover.
This was an adaptation of the play "Elizabeth the Queen" by Maxwell Anderson. The stage production opened at the Guild Theatre in New York on November 3, 1930 starring legendary married couple Lynn Fontanne and Alfred Lunt. The play ran for 147 performances. The title of the movie was to be the same as the play, but Errol Flynn protested that he wanted his presence acknowledged in the title. The choice of "The Knight and the Lady" upset Bette Davis, and "Elizabeth and Essex" was a book title already copyrighted. "The Private Lives of Elizabeth and Essex" was chosen to fit in the motif of The Private Life of Henry VIII. (1933) and The Private Life of Don Juan (1934). For several years, from the time of Errol Flynn's death until the film was issued on videocassette and began to be shown on Turner Classic Movies, the title was changed to "Elizabeth the Queen", after which it was restored to "The Private Lives...".
When MGM signed Alfred Lunt and Lynn Fontanne to a movie contract in 1931, they bought the rights to "Elizabeth the Queen" as well as two of the Lunts' other stage successes, "The Guardsman" and "Reunion in Vienna." After the Lunts' first film together, The Guardsman (1931), flopped at the box office, MGM canceled the Lunts' contract, made Reunion in Vienna (1933) with other actors (John Barrymore, Lionel Barrymore and Diana Wynyard), and put "Elizabeth the Queen" on hold until they later sold the rights to Warner Brothers. But a sequence of the Lunts playing the final scene from "Elizabeth the Queen" appears at the start of "The Guardsman" in a play-within-a-film context.
According to syndicated newspaper reporter Sheilah Graham, the gowns worn by Bette Davis weighed as much as 60 pounds, and under the studio lights, Davis was loosing two or three pounds per day while working on this film.